This study analyzes expenditure categories of travelers on their summer holiday trips, jointly with the effects of travel duration, number of travel companions, and travel type. Results of the almost ideal demand system (AIDS) estimation on data from 1,113 Korean respondents reveal strong interrelationships among expenditure, own‐price, and cross‐price elasticities in the total travel‐related consumption behaviors. This study of a system‐of‐equations approach serves as a launch pad for ongoing work by jointly modeling effects of trip characteristics and prices through a comprehensive, nonlinear AIDS approach and reflecting destination price changes for Koreans who traveled during their summer holidays.